When the classroom door opens the students find a locked box with the following note: You have to help us! We are historians studying the inventions of the Renaissance. We stumbled upon a new page in Leonardo Da Vinci’s notebook describing a “Time Changer.” Little did we know that it would propel us back in time! We are stuck in the Renaissance! Inside this locked box is a series of instructions to build Da Vinci’s Time Changer. Once the time changer is built you can call us back!. We had to lock it up so that it would not be found before this date. Since we went back to the Renaissance at this exact moment, we are only able to return when it is our own time! Please help us return to our lives! You have 45 minutes.